The Morality of Unenabled Embryo Use—Arguments That Work and Arguments That Don't
2004; Elsevier BV; Volume: 79; Issue: 6 Linguagem: Inglês
10.1016/s0025-6196(11)62634-7
ISSN1942-5546
Autores Tópico(s)Ethics and Legal Issues in Pediatric Healthcare
ResumoAs natural phenomena are to the scientist, so are arguments to the philosopher. The philosopher Richard Hare once said, “I like to give arguments for my position. They come in handy when people don't agree with me.” Consider then the inclination of many among us—perhaps by virtue of being busy, or for other reasons—to pronounce a verdict, when a moral controversy comes along, by consulting aphorisms or slogans. By following this inclination, earnest people may unwittingly betray the moral views that they aspire to uphold. For they may fail to take account of the depth and subtlety of their respective moral views. I should like to discuss arguments offered in support of using human embryos in research and therapy. I plan to survey both arguments that work and arguments that do not. I shall first review six arguments that I place in the latter category. Each of these purports to justify research that I happen to support. But inasmuch as a good case is not made better by overstatement, and no case is made by an unsound argument, I am going to disavow those six arguments. I urge other supporters of donated embryo use to disavow them as well, because, as Bernard Williams once said, openness to criticism is the homage that candor pays to truth. To support my own view, I shall go on to sketch arguments that, so I shall suggest, are sound. I shall then say a bit more about cloning in particular, and shall close by remarking on the risk of abuses. Consider the argument that the imminent death of an embryo—for instance, a surplus embryo in a fertility clinic—justifies its consumption in research. A more extreme proposal, recently offered by Frederick Grinnell, would have us define a concept of embryo death according to which embryos not destined for intrauterine transfer are dead. This concept of death seems to defy common sense. The embryos that I contemplate as research subjects are alive. About this concept of death I doubt that it is necessary to say anything more. Let us consider the plain argument that imminent death of an admittedly living embryo justifies killing it in research. In refutation of that argument, consider the following Wild West example. One day the notorious varmint Hatfield is riding about on his horse. Feeling tired, Hatfield elects to dismount beside the railroad tracks. He sits down, and eventually dozes off, stretching out across the tracks. Sometime later, as Hatfield lies sound asleep astride the tracks, a train approaches at high speed. Whereupon there happens to ride onto the scene Hatfield's archenemy, McCoy. Spotting Hatfield, McCoy gallops to the tracks, dismounts, and—just in the nick of time before the train arrives—yanks Hatfield from the tracks. McCoy then immediately pulls out his rifle, trains it on Hatfield, and kills Hatfield. In this case, even though Hatfield would have died under the wheels of the train a split second earlier, we hold McCoy guilty of wrongful killing. In general, the imminent death of a victim does not justify its killing. Embryo research will not be justifiable solely on the ground of imminent embryo death. The nonindividuation objection to zygotic personhood runs as follows. Prior to formation of an embryo's primitive streak at day 14 of development, it can happen that the embryo splits into monozygotic twins. And if twinning occurs, the twins can fuse. Hence it has been suggested that in respect of any embryo, one cannot say until day 14 whether there exists one individual or more. If one cannot say how many persons exist, it is untenable to say that any person exists. Another version of the nonindividuation objection begins from the premise that in twinning, an embryo vanishes and leaves no earthly remains. How could an individual person die leaving no earthly remains? If no corpse ever exists, there could not earlier have existed a person. Thus does the nonindividuation objection characterize zygotic personhood as metaphysically impossible. The objection's biological sophistication has led many scientists to regard it as a clinching argument for embryo use. Despite that sophistication, the nonindividuation objection is susceptible to the following refutation owed to David Oderberg.1Oderberg DS Modal properties, moral status, and identity.Philos Public Aff. 1997; 26: 259-298Crossref Scopus (36) Google Scholar Suppose at time t0 a somatic cell x. By t1, x has divided, and there exist x’s daughter cells d1 and d2. The process by which this has occurred, namely, mitosis, is routine. Notice that as we look back at the history of x up to t1, we do not have any doubt that x was an individual cell. Plainly x had the capability of dividing, and in fact, x did divide, but it is not incoherent to say, and we unhesitatingly do say, that for so long as x existed, x was an individual. As for the apparent puzzle of dying without leaving earthly remains, again a reflection on mitosis sheds light. Necrosis is not the only means by which a life form may cease to exist. Dividing is another means. And it happens that after division, there is no corpse. So it is not metaphysically incoherent to say that an embryo capable of dividing is an individual. Or that an embryo that does divide was an individual before it divided. To rehabilitate the nonindividuation objection, a proponent might contend that indivisibility is somehow intrinsic to the individuality of a person as it may not be to the individuality of a cell, so that a being that is divisible cannot be or correspond to a person. To buttress this claim, the proponent might offer the example that an adult individual cannot divide into surviving individuals. Or the proponent might contend that even if adult individual x could be split into surviving individuals—say, by a brain split and transplant operation in which, as imagined by philosophers of mind, x’s brain is split and each half is transferred into a new body so that each successor retains memories and otherwise achieves psychological continuity with x—it would not be the case that x is the same individual as either of its successors. One reply to this, owed to the whimsy of Peter King, is that it is possible to survive with only half a brain, though in such case one is restricted to a career in politics. But we may leave aside what adults can do. We may reply to the proponent of the nonindividuation objection with two thoughts. First, what is feasible for an adult ought not constrain our thinking, because we know of the remarkable ability of an early embryo to split into surviving individuals. Second, the individuality of a being does not depend on its being the same individual, if it happens to split, as any of its successors. When an embryo has split, we may simply say that it was one individual until it split, that the individual ceased to exist when it split, and that two individuals have succeeded it. Thus may we render not only the possibility but the actuality of twinning consistent with individuality of the original embryo and with individuality of its twin successors. Given that the case of an embryo that does split resolves in this way, no impediment arises to individuality of an embryo that has not split. According to this analysis, the nonindividuation objection fails to establish that an embryo cannot be a person. When monozygotic twinning occurs, it may be said that two persons succeed one person that ceases. But even if we defeat the contention that an embryo cannot be a person, there remains the question whether, for purposes of the duty not to kill, we should treat every embryo as a person. That a being “is a person” is not an empirical observation or an a priori truth. Calling a being a person is a shorthand reply to the moral question, “How should we treat it for this purpose?” The shorthand signifies our conclusion that we should classify the being among those to whom we think all of us should accord a particular treatment. Whereupon we may fairly be asked what argument supports that conclusion. Failure of the nonindividuation objection leaves the door open to introduce, or oppose, arguments that we are obliged to treat all embryos as persons for purposes of the duty not to kill. Utilitarianism commands us to maximize aggregate preference satisfaction for the universe of affected sentient beings. A familiar argument is that if, in regenerative medicine, we sacrifice a relatively small number of embryos in order to help millions, perhaps billions, of suffering people, we can achieve higher aggregate preference satisfaction than we would achieve were we to classify every embryo as a person for purposes of the duty not to kill. John Stuart Mill, who with Bentham brought utilitarianism to prominence, learned calculus at the age of five, but Mill did not envision the mathematical defect of his moral theory. The infirmity came to light through the work of economists in the twentieth century. Consider that the number of affected sentient beings in respect of many policy issues, embryo use among them, is enormous. Collecting utility data from so many people would be a monumental task. A more fundamental failing is that there obtains no method of measuring utility. Utilitarianism presupposes a utility function for each member of the set of affected beings. A utility function is nowadays understood as a real-valued order homomorphism representing a transitive and connected binary relation defined by an individual on a set of alternatives. This understanding no doubt explains why many scientists have felt comfortable with utilitarianism and with a utilitarian defense of embryo research. Utilitarianism seems empirical, quantitative, precise. For physician scientists, utilitarianism evokes some of the thinking to which outcome studies, comparing benefits and costs, have accustomed them. But if, for two or more individuals, a utilitarian seeks to sum the utilities of a given alternative, there obtains no common unit of measure. Indeed there does not exist a standard measure even for a single person. While it is easy to define, as a representation of an individual's positioning of alternatives, a real-valued order homomorphism, any of infinitely many other functions formed by affine transformations from that order homomorphism will also represent the positioning. Though the problem of interpersonal incommensurability of utilities remains unsolved, on many occasions a utilitarian's audience either will be unaware of the problem, or willing to overlook it. For example, if a hospital were to propose construction of a new facility, and if that project would require demolition of the homes of 100 people, displacing those residents in exchange for reimbursement of their homes’ fair market value and their moving expenses, a utilitarian might argue that future gains in utility produced by the project for perhaps hundreds of thousands of patients in future decades will exceed the disutility of the 100 who must presently relocate. Listeners will follow an argument such as this without worrying much about whether the utility calculation has been performed. For it may seem in such a case that for any plausible conversion ratio of units of measure, the comparison of utility between alternatives will be lopsided. On the other hand, if an advocated alternative is the killing of a life form that some people sincerely believe to be a person, not much tolerance will be found for an argument whose proponents cannot produce the calculation on which the argument purportedly rests. The root of the difficulty is the same as in the blinkered attempt to order, on the basis of supposed measures of quality, incommensurable college football teams. The next argument, also not infrequently invoked by scientists, proceeds by asserting that public advocacy concerning embryo use should appeal to “fact-based reasoning” alone, and that it therefore follows that objections resting on any other ground must give way to the progress of biomedical science. This argument serves as a euphemism for saying that appeals to religion and various “insular” moral views do not have a place in public debate about science. In reply, we must observe that the view that scientific work grounded in fact-based reasoning should go forward without obstruction by moral views is itself a moral view. When an objection lies on grounds of wrongful killing, it is neither appropriate nor feasible to oust religion or moral views from the conversation. Of course we all agree that we should rest on facts as opposed to errors, but given facts, a normative discussion awaits. A more sophisticated cousin of the foregoing argument, the call to “public reason” of John Rawls, would have us employ in public discourse only premises that others could not reasonably reject.2Rawls J Political Liberalism. Columbia University Press, New York, NY1993Google Scholar That, in a moment, is what I shall try to do in stating my own view. It has been suggested that even if the consumption of embryos in research is wrong, a government could support derivative research by eschewing complicity in the destruction of embryos. As it has been put by proponents of this move, one could distinguish between embryonic stem cell derivation and embryonic stem cell use. The National Institutes of Health (NIH) at one time adopted this view.365 Fed. Reg. 51976-51981 (2000).Google Scholar It announced that it would fund projects classified as embryonic stem cell use. The notion seemed to be that this would avoid complicity in wrongful embryo-destructive derivation of stem cells. In another scheme for purportedly conducting embryo research without complicity in embryo killing, fertility clinicians would perform the immunosurgery by which embryonic stem cells are derived from embryos. This scheme is probably impractical, because fertility clinicians do not do that kind of work. They do not customarily derive cell lines from embryos; they customarily nurture and transfer embryos so as to achieve pregnancies. Even if the scheme were practical, it shares with the derivation-use distinction the problem that when a chain of supply runs from someone who sacrifices an embryo to someone who experiments with the sacrificed embryo's derivatives, we seem compelled to say from a moral point of view that the source and the recipient ride in the same boat. It is untenable to say that the experimenter is not complicit in the work of the supplier. Another noncomplicity strategy, recently played out in the United States, might be called “government surprise.” It would begin as a government announces that it will not fund research that effects or is consequent on destruction of embryos. Then, after this policy has become widely known, the government suddenly announces—in the United States, we saw this happen on August 9, 2001—that in the future it will disperse public funds for studies using derivatives of embryos already then sacrificed. The most cogent philosophical defense of this gambit that occurs to me might be to say that the government had not, prior to the second announcement, induced any destruction of embryos. One would say this on the hypothesis that theretofore, the government had given everyone to believe that it would not support such research. (The hypothesis may not be true with respect to the recent history of US government policy. Between the first and second announcements came the just mentioned NIH announcement that it would fund research on embryonic derivatives. What I am here calling the first announcement was a prohibition enacted by Congress as a rider to an appropriations bill.4Pub. L. No. 104-99, Title I, §128, 110 Stat. 26, 34 (1996).Google Scholar) But apart from this historical contingency, the government surprise scheme succumbs to the same objection that lodges against the two other schemes that I have just mentioned. The government surprise scheme would place those who participate in funded embryonic stem cell studies in the same boat with those who participate in nonfunded embryodestructive stem cell derivation. The last in my roster of arguments that do not work consists in the claim that somatic cell nuclear transfer performed in research is not cloning, and does not produce clones or embryos, this because a suggested new semantic regimen would withhold the term “cloning” from any instance of somatic cell nuclear transfer in research, would instead call the process “nuclear transplantation,” and would withhold “clone” and “embryo” from the products of that process. For this context, I have elsewhere tried to sort out the relevant entities and events in a manner informed by biological and moral considerations. My analysis leads me to reject the proposed semantic regimen as to both process and products. The proposed terminology risks the appearance of trying to smuggle in a morally significant event— initiation of embryogenesis—by not mentioning it. In trying to withhold “cloning” and “clone” from processes and products of research, a proponent of the proposed terminology would contradict the ordinary and morally significant understanding of cloning as a genetic event, an event completed shortly after oocyte activation, regardless whether transfer to a uterus ensues. The goal that has motivated the proposed terminology, the goal of offering the public a sharp distinction between research and producing children, does not require legerdemain to attain. Rather we may implement a simple distinction, a distinction between “procreative cloning” and “nonprocreative cloning.” The distinction turns on a single observable event, intrauterine transfer.5Guenin LM The set of embryo subjects.Nat Biotechnol. 2003; 21: 482-483Crossref PubMed Scopus (9) Google Scholar As for “embryo,” any being that is of a kind capable of developing into a neonate upon transfer to a uterus is an object of moral concern. We implicitly acknowledge that concern when we classify every prefetal developing organism as an embryo. (In both scientific writing and popular speech, we have abandoned the textbook definition according to which “embryo” applies only to a conceptus older than two weeks.) Recognition of a being as an embryo does not end our moral investigation. We may conclude—for reasons that I shall shortly present, I believe that we should conclude—that we are not obliged to treat every embryo in the same way. But in respect of a product of somatic cell nuclear transfer, recognizing its inclusion within a discussant's universe of moral concern is the place from which to begin our discussion with one who does not agree with us. To advance the proposition that embryonic stem cell research is virtuous if not obligatory, I have elsewhere presented an argument that I call “the argument from nonenablement.”6Guenin LM Morals and primordials.Science. 2001; 292: 1659-1660Crossref PubMed Scopus (22) Google Scholar I refer to an embryo that will never enter a uterus as an “unenabled” embryo. In the first instance, I have in mind a situation, which often arises with fertility patients, in which the one person in the world who, together with her partner, is empowered to decide about intrauterine transfer of an embryo formed from her oocyte decides that neither does she wish to have that embryo transferred unto her nor does she wish to give the embryo to anyone else for intrauterine transfer. There is no moral view of which I know that asserts a duty of intrauterine embryo transfer. That is to say that there is no moral view that asserts that a woman lies under a duty to undergo a transfer unto her of an embryo that lies outside her. About such a procedure, we respect her autonomy. Imagine, therefore, that a woman declines intrauterine transfer, and in fact, forbids it. She, with her partner, donates to medicine either an embryo created during her fertility treatment, or an embryo that will be created by a scientist from their donated cells. Let us assume that this decision is final and that the embryo has left parental control. Such a donation to medicine I call an “epidosembryo.” I take this name from the Greek epidosis for a citizen's great beneficence to the common weal. What Dr. Will and Dr. Charlie Mayo left to Minnesota, and to the world, was an epidosis. So too may we describe a couple's gift to medicine of a life form that, were they to decide otherwise, could become their child. A distinction obtains between the developmental potential of an embryo that lies in a petri dish and will remain there, and an embryo that lies in a uterus, however it got there. In consequence of parental instructions that an epidosembryo shall be used in research or therapy and shall not be transferred to a uterus, there does not obtain any morally significant chance that from such an embryo, an infant will develop. To put the matter in language that I owe to Hare,7Hare RM Essays on Bioethics. Clarendon Press, Oxford, England1993Google Scholar no possible person corresponds to an epidosembryo. We also know, and this is purely empirical knowledge, that an embryo is not sentient. And that, for lack of a cortex, an embryo cannot form preferences. Nor can an embryo adopt ends. Therefore nothing that we might do to an epidosembryo can cause it discomfort or frustrate it. Under these circumstances, and when we consider the duty of mutual aid asserted within each of the leading moral views of our time, I claim that it is permissible to use some embryos, namely epidosembryos, in medicine. As the preceding discussion makes clear, I rest the permissibility and virtuousness of epidosembryo use on the autonomous decisions of couples from whose cells such embryos originate. The moral analysis flows entirely from what it is that they decide. If it is permissible for those donations to be made, then it is permissible for recipient scientists to use epidosembryos as instructed. Suppose that someone interjects that precisely because epidosembryos cannot form preferences, it is our obligation to act according to their advantage. I reply that we cannot promote any advantage of epidosembryos. Were we to refrain from using epidosembryos in research, we could not gain anything for them. Entry into the only environment by which they could attain birth has been forbidden by the only persons in the world empowered to decide on entry into that environment. I also point out that the argument from nonenablement differs from an appeal to imminent death as a means of justifying a killing. Nonenablement precludes a conceptus from attaining any of the attributes—autonomy, ability to feel pain, preferences, and, according to the traditional Thomist-Aristotelian teaching of Christianity, the attainment of a soul—whose infringement makes killing wrong. Nonenablement entails that there does not even correspond to an epidosembryo a possible person. It is not that death is imminent, but that development is bounded. Let me now reply to a couple objections. The first objection asserts that the sacrifice of an embryo violates the second form of Kant's categorical imperative, the precept that we should treat “humanity … always at the same time as an end, never merely as a means.”8Kant Groundwork of the Metaphysic of Morals.in: Gregor MJ The Cambridge Edition of the Works of Immanuel Kant, Practical Philosophy. 4. Cambridge University Press, Cambridge, England1996: 429Google Scholar (This, not the Declaration of Helsinki, is the origin of the requirement of informed consent.) In this formulation, by “humanity” Kant understands rational nature. For this reason, the objection misapprehends Kant's view, which applies only to rational beings. The second form of the categorical imperative does not apply to mentally incompetent adults, infants, or embryos. That is not to say that Kant would take a cavalier view of the helpless. Kant would analyze our moral obligations toward these nonrational human beings as he would analyze moral questions in general. (“Human being,” by the way, is not a decisive moral classification; the phrase obviously applies to any being of the species Homo sapiens, including any somatic cell.) Kant would ask whether we could without contradiction of the will adopt as a universal law whatever maxim we propose about how we shall treat such a being. We do not contradict our will by adopting as a universal law that we shall use epidosembryos, at no cost in potential lives, to provide to those who suffer the aid that we would wish were we in their shoes. A second objection is the simple declaration that a zygote is a person. The most influential version of that objection appears in the official teaching issued within the latter part of the twentieth century by the Sacred Congregation for the Doctrine of the Faith of the Roman Catholic Church. The reasoning begins from the premise that all artificial methods of reproduction, including in vitro fertilization, are illicit. In adopting that stance, the magisterium anticipated a situation now upon us—a set of surplus embryos whose creators have effectively consigned them, as the magisterium puts it, to an “absurd fate.” Such embryos will either perish as waste or be frozen indefinitely, never entering a womb. So when the magisterium condemns embryo destruction, it speaks consistently. It condemns destruction of embryos in research just as it condemns artificial reproductive practices that inexorably lead to destruction of embryos as waste. Others who approve of in vitro fertilization as presently practiced but oppose use of embryos in research fall into inconsistency. They implicitly approve the destruction of surplus embryos as waste while condemning the use of surplus embryos to help others. Although the official Catholic view cannot be accused of inconsistency in the foregoing respect, on what ground does that view rest? Why condemn the destruction of an unenabled embryo in research? As one studies the magisterial instructions and looks for arguments, one finds a single argument. The argument is not scriptural. The ancients did not understand fertilization or embryogenesis, and were not thinking of embryos in petri dishes. The argument purports to be biological. The argument is that because fertilization creates a new genome, fertilization creates a person.9Sacred Congregation for the Doctrine of the Faith. Donum Vitae. Vatican City; 1987.Google Scholar This is an argument whose premise one must admit— the biology is correct, fertilization does produce a new genome—but whose conclusion does not follow. The argument presupposes a radical version of genetic reductionism. To say that a person is a genome is a view that even a materialist would not venture. It is a view contradicting the belief, held within the religious tradition from within which the argument is offered, that a person is a corpore et anima unus, a union of body and soul. I imagine that one reason that many people have not heard this argument is that it cannot be maintained consistently with the rest of Christian teaching. I suspect that eventually the argument will fade. Another interpretation of Catholicism might lay stress on the notion, also advanced by the magisterium, that because we do not know whether an embryo is a person, we should exercise caution, and act as if it were a person. But suppose that we could have a conversation with God. We would say that as of 1998, we discovered how to culture embryonic stem cells. We would explain that we have plans to relieve human suffering by the use of embryos that will never enter a womb. Is it plausible that He would tell us that He regards embryos that will never enter a womb as persons in the sense that He includes them in the universe of beings that He wishes us not to consume? I do not know of a tenable argument according to which an all-merciful and omniscient God would assert that preference. For He would know that unenabled embryos will never develop into infants. He would know that our efforts to aid actual lives would exact no cost in potential lives. Under these circumstances, there inexorably come to bear Christian social teachings, including the duty to love thy neighbor as thyself, and “the law of charity.”10Congregation for the Doctrine of the Faith. Declarato de Abortu Procurato Vatican City; 1974.Google Scholar You may have heard some people say that the justification of embryonic stem cell research lies in the circumstance that the embryo donors initially intended procreation when they created the embryos now regarded as surplus. The argument from nonenablement does not rely on any assumption of initial procreative intent. Hence the argument from nonenablement justifies not only embryonic stem cell research, but nonprocreative cloning. An objection peculiar to cloning might be this. An oocyte is created for a purpose, namely to issue in offspring, and it is wrong to divert an oocyte to any other purpose. This objection rests on an Aristotelian teleology that, since Darwin, does not exert much grip on our thought. We have learned from the history of medicine how mistaken we humans have often been in inferring purposes of various cells and structures of the human body. Our forbears would have said that bones are what hold us up; today we think of the marrow as a blood factory, and think it entirely appropriate to transfer marrow from one patient to another. We have learned the remarkable adaptability of tissues and cells. We now actively engage in directing tissues and cells to serve chosen purposes in aid of sick patients, calling this treatment “conventional” drug therapy. It is unpersuasive to say that an oocyte can or should serve only one purpose. From a religious point of view—and the teleological objection that I have just described now finds its greatest support in religious traditions—the ultimate arbiter is divine will. Imagine again that we could have a conversation with God. Would He say that oocytes may serve only the purpose of
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